Yes, this is a training forum, so of course that’s the main topic of conversation. And everyone loves those marginal gains. But neither of these is performance. Performance is the race result. (Though you can and should have other process/execution goals too).
So many of us are losing sight of the single biggest improvement a fairly fit racer can make: execution. Execution is using strategy and tactics to maximize your performance given your fitness, your strengths, your competitors weaknesses, the course, line choices, other’s attacks, etc.
This NorCal Cycling video is a great example. EJ is a newb racer with great fitness and equipment. He’s also got a great mentor. But he still gets much worse race results than he could because all he does is burn matches and fail to sit in drafts. You can watch any of his race analysis and see this. Jeff compared his actual data in a race to what it would take just without drafting and the power required doubles.
But that actually undersells it, because if you consider harder than necessary accelerations due to poor line choice, excessive braking, dumb attacks, that number would go up even more, plus those peaks will create disproportionate fatigue.